Foldable bag

Abstract

This foldable bag (A) includes a container main body (B) having: a set of foldable surfaces (5) positioned on a front surface and a rear surface when the foldable bag is in a folded state; inner bottom pleats (6) formed from one longitudinal end side (M1) of each of the foldable surfaces toward an inner other end side, and having a width corresponding to a bottom gusset (20); a plurality of sets of top inner pleats (7,8) formed from the other longitudinal end side (M2) of each of the foldable surfaces toward an inner one end side, and having pleat widths that become gradually narrower toward the inner-facing side. After use, the container main body can be flipped over and folded into a flat rectangular shape by tensioning bundling end parts (C), at which side end parts (4) are sealed, in a direction pulling the bundling end pails apart.

The invention claimed is: 
     
       1. A foldable bag that is foldable into a rectangular flat shape, comprising:
 a storage main body having a set of folding surfaces located on front and rear sides when the foldable bag is folded into the rectangular flat shape, an inner bottom pleat formed from one end side inwardly toward another end side of both front and rear folding surfaces in a longitudinal direction and having a width corresponding to a bottom gusset, and a plurality of sets of inner top pleats formed from the other end side inwardly toward the one end side of the front and rear folding surfaces in the longitudinal direction and having a width that becomes gradually narrower inwardly toward an opposing side; 
 a storage entrance part for insertion and removal of an article to be stored, the storage entrance part being formed on an innermost side of the plurality of sets of inner top pleats of the folded storage main body; 
 a set of bundle end parts sewn to folded side end portions of the storage main body to seal side ends of the inner bottom pleat and the plurality of sets of inner top pleats formed in the folded storage main body in a stacked state; and 
 a handle attached outside the storage entrance part of the folded storage main body, 
 wherein the storage main body is foldable by turning the foldable bag in a usable state inside out and tensioning the set of bundle end parts in directions away from each other. 
 
     
     
       2. The foldable bag according to  claim 1 , wherein
 the storage main body comprises a rectangular sheet material defined by long sides and short sides, and 
 the sheet material is foldable along a first valley fold line formed on a perpendicular bisector of the long sides; a set of first mountain fold lines formed at a spacing S 1  that is half a width of the bottom gusset from the first valley fold line toward the short sides and corresponding to the one end side of the front and rear folding surfaces in the longitudinal direction: a set of second mountain fold lines formed at a spacing S 2  that is twice or more the spacing S 1  from the first mountain fold lines toward the short sides and corresponding to the other end side of the front and rear folding surfaces in the longitudinal direction; a set of second valley fold lines formed at a spacing S 3  narrower than the spacing S 1  from the second mountain fold lines toward the short sides and corresponding to first inner top pleats; a set of third mountain fold lines formed at the spacing S 3  from the second valley fold lines toward the short sides and corresponding to second inner top pleats; and a plurality of sets of valley fold lines and mountain fold lines formed at a spacing that becomes gradually narrower than the spacing S 3  from the third mountain fold lines toward the short sides. 
 
     
     
       3. The foldable bag according to  claim 1 , wherein the storage main body includes a zipper for opening and closing the storage entrance part along the storage entrance part.